In New Zealand, most dairy animals such as cows are generally milked twice daily, the milk being collected into a main storage vat before being transported in bulk to a milk treatment station.
The milk is then processed into a range of products, including pasteurised milk, powdered milk, butter, cheese or milk derivatives.
The production of butter and cheese results in large volumes of by-products such as whey which can be further processed on-site or transported to another specialist treatment station. A number of components can be fractionated from such milk by-products including carbohydrates, whey protein bioactives such as lactoferrin and so forth.
The standard processing of milk and milk by-products thus results in high transport and handling costs associated with processing such large volumes of milk.
Further, due to the time delay between the collection of milk on-farm and its subsequent processing off site, milk proteins such as bioactives may be subjected to proteolytic degradation by enzymes such as proteases, or may be inactivated or lose activity through a number of other interactions.
The act of transporting and processing the milk may also denature a number of bioactive proteins through the physical handling or heating of the liquid.
To attempt to overcome some of these problems, NZ 280724 disclosed a process for the isolation of endogenous milk proteins by on-farm processing of milk using standard separation techniques such as chromatographic resins.
Such processes were useful in the separation of bioactive proteins in the minimum amount of time, ensuring minimal degradation or loss of activity of the bioactive proteins.
However, while these methods work well in an experimental situation, the volume of milk collected during a standard milking often meant such standard separation techniques were not optimal.
Chromatographic resins are primarily designed to process small volumes of liquid, usually at low flow rates to ensure good component separation. Increasing the flow rate not only reduces the degree of separation but may damage the resin or chromatographic column. As large amounts of resin would be required to cope with normal milking volumes without overloading, these techniques may be prohibitively expensive.
All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does hot constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.
It is acknowledged that the term ‘comprise’ may, under varying jurisdictions, be attributed with either an exclusive or an inclusive meaning. For the purpose of this specification, and unless otherwise noted, the term ‘comprise’ shall have an inclusive meaning—i.e. that it will be taken to mean an inclusion of not only the listed components it directly references, but also other non-specified components or elements. This rationale will also be used when the term ‘comprised’ or ‘comprising’ is used in relation to one or more steps in a method or process.
It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.
Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.